Fuel preheater and economizer



1963 A. J. LUNDI FUEL PREHEATER AND ECONOMIZER 2 Sheets-Sheet 1.

Filed April 24, 1961 k n E a w 1N VENTOR.

Nov. 12, 1963 -A. J. LUNDl 3,110,296

FUEL PREHEATER AND ECONQMIZER Filed April 24, 1961 2 Sheets-Sheet 2 1 N VEN TOR. mm. BY @900 Attorneys and / I I I I Axe/J Lund/ I I I I I I I I I I I I lnl II I I I III I l IIIIIIII v m l Ill -u Hi I I II I I l I 4 l 4 w 1k. I"! vn I I l I I l I l l I l l III IIII H ll I I mv wk om w United States Patent Ofiice 3 ,ll-,2% Patented Nov. 12, 1963 3,11%,296 FUEL PREHEA TER Ahll) ECQNQMHZER Axel J. Lundi, 1633 N. 43rd Ave, Stone Park, Hill. Filed Apr. 24, 1961, Ser. No. 105,096 7 Claims. (Cl. l23122) This invention comprises a novel and useful preheater and economizer and more particularly relates to a device for preheating the liquid fuel supplied from an engine fuel pump to the carburetor of an engine.

A further object of the invention is to provide a device in accordance with the preceding object in which the heat employed for preheating the liquid fuel is derived from the water circulating cooling system of an internal combustion engine.

Yet another object of the invention is to provide a gasoline preheater which shall provide an inbuilt reservoir for retaining heat for some time after cessation of the engine operation in readiness for preheating the fuel when the engine is again started.

Yet another object of the invention is to provide a device in accordance with the preceding objects which will enable all or any portion of the liquid fuel delivered by the engine fuel pump to be supplied alternatively to the preheater from the carburetor or directly to the carburetor in controllable proportions.

A still further important object of the invention is to provide a preheater in accordance with the preceding objects wherein a spiral heating coil carrying the liquid fuel to the preheater is immersed in heated water circulated through a tank by the engine water circulating cooling system and in which an improved relation is obtained bet-ween the spiral heating coil and the heated water to effect an improved, more rapid and more efficient heat exchange relation between the hot water and the liquid fuel and with a minimum obstruction to flow of the cooling water through the device.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FEGURE 1 is an elevational view showing a portion of an internal combustion engine and its water cooling system to which the principles of the present invention have been app-lied in a preferred embodiment;

FIGURE 2 is a perspective view of the preheater element of the invention;

FKGURE 3 is a view in vertical longitudinal section through the preheater of FIGURE 2, taken upon an enlarged scale, and relative flow of fluids therein being indicated by arrows;

FZGURE 4 is a vertical transverse sectional and detailed view taken substantially upon the plane indicated by the section line 4-4 of FlGURE 3; and

FIGURE 5 is a further detailed view of the left end portion of FIGURE 3 but showing a slightly modified construction.

The present invention contemplates both a novel and advantageous preheating device which may be readily applied to conventional'internal combustion engines of the type employing as a part thereof a water circulating cooling system together with a source of fuel such as a fuel pump and a carburetor forming a combustible mixture to be supplied to the engine, as well as the entire fuel supply system incorporated into such an engine.

Referring first to FIGURE 1 which illustrates a typical manner of applying the principles of the invention, there is indicated generally by the numeral to an internal combustion engine of any suitable type which includes as conventional elements thereof a carburetor 12 by means of which a combustible mixture is delivered to the interior of the internal combustion engine together with a source of fuel such as a fuel pump 14 which receives fuel from a fuel tank, not shown, or any other suitable source such as the fuel suction line .16. 'lhe engine further includes any conventional type of circulating water cooling system, a portion of which only is indicated by the Water hoses l8 and 2t it being understood that water is circulated by means of these hoses through the engine block and water jacket, not shown, and through the engine cooling radiator, the usual engine driven cooling fan 22 being provided to efiect circulation of air through this radiator in a well known manner.

In accordance with the present invention there is applied to an engine of this general type a preheater unit indicated generally by the numeral 3% and which forms an essential component of the present invention. A pair of heated water inlet and outlet conduits 32 and 34 communicate with the interior of the preheater at opposite ends thereof for circulating heated water therethrough, these conduits being suitably connected in any desired manner, not shown, with the water circulating system of the internal combustion engine for supplying water heated by the operation of the engine to the preheater unit 3% Suitable pipe or conduit means are provided to be hereinafter described in detail which connect the fuel pump 14- with the carburetor l2 and with the preheater unit 30 for selectively and proportionately delivering liquid fuel from the carburetor either to the heater or to the carburetor directly or to both.

Referring now primarily to FIGURE 3 in conjunction with FEGURES 2 and 4 it will be observed that the prehea-ter unit 31 consists of an elongated preferably cylindrical tank 41 whose open ends are closed as by a pair of end walls 42 and 44. The tank is preferably disposed in a generally horizontal position and is provided with a mounting bracket consisting of an arcuate plate 4-5 snugly embracing and secured as by welding to the underside of the tank so, which plate has an angulated downturned mounting flange 48 thereon, apertured as shown at 59 in FIGURE 2, these apertures being so tor-med and the plate being so constructed as to provide a convenient means by which the preheater unit 3%) may be readily attached to any suitable portion of the internal combustion engine adjacent to the carburetor. Inasmuch as the actual location and type of fastening by which the mounting bracket is secured to the engine will vary with difierent means of engines, and since the details of this mounting in themselves form no part of this invention as claimed hereinafter, a further description of the same is deemed to be unnecessary.

Continuing to refer to FlGURE 3 it will be observed that the two end walls 42 and 34 comprise circular plates which are received Within the open ends of the cylindrical tank 46 and may be permanently mounted therein as by welding or the like, by screw-threaded engagement or by any other suitable fastening means, it being only necessary that they provide a secure fluid-tight closure for the ends of the tank. A pair of tubular bosses 60 and 62 are secured to, extend through and are disposed axially outwardly from the end plates or end walls 42 and 5 4 in alignment with each other. The previously mentioned water inlet and outlet conduits 32 and 34 which may comprise rubber hose or the like telescopingly embrace these bosses as shown in FIGURE 3 and are secured thereto by any suitable type of clamping means such as that indicated at 64. It will be observed that by this arrangement heated water from the engine water circulating cooling system is caused to pass 1ongi--- tudinally, centrally and ain'ally into and out of the tank; 41 in a straight line flow.

The tank is preferably of sufficient size to contain; therein a sufficient quantity of water so that it will constitute a heat reservoir in which the heated water is avail-- able, even for a considerable time after the operation. of the engine has ceased, as a means for preheating thefuel for the next starting of the engine.

Disposed within the tank at} is a spiral heating coil 70 having a series of longitudinally spaced convolutions, thisv coil having its central axis disposed preferably along the central line of the two bosses 6S and 62 so that the sides. and ends of the heating coil are substantially uniformly spaced from and at a selected distance from the cylin drical wall of the tank 40 and the two end walls 42 and 44 thereof. The size of the convolut'ions or diameter thereof is preferably such that the hollow passage through the spiral 'coil will embrace the normal straight: line flow of the heating water from the boss 69' to the boss 62 in the direction indicated by the arrows in that. figure.

The effect of this arrangement is such that the spiral configuration of the coil as the heated wa er flows therethrough will impart to this water a corresponding spiraling flow, thereby increasing the surface contact of the heated water with the coil and promoting both the ef-- ficiency ad the rate of heat exchange therebetween. However, the configuration of the coil is such as to inapart very little obstruction to normal flow through the:

device and therefore will minimize any obstruction to normal circulation of the cooling water in the engine.

circulating Water cooling system.

'of any suitable construction with a further conduit '78 having a T-fitting 843 which in turn is connected to the discharge or delivery conduit 82 of the fuel pump 14. The delivery conduit 74 of the preheater unit communicates with a T-fitting 84 which through the conduit 86 communicates with the carburetor 12 for delivering heated fuel thereto. The further conduit 88 connects the T-fitting 84 with the previously mentioned T-fitting 8% of the delivery conduit 82 of the fuel pump.

It will thus be observed that a pair of alternative pas sages connect the fuel pump with the carburetor. Thus, by varying the degree of opening of the valve 76, the liquid fuel delivered by the fuel pump 14 may be caused to pass either directly through the conduit 83, T-fitting 84 and conduit 86 to the carburetor or may be caused to pass primarily through the conduit 72 into the heating coil 75) and from thence through the conduit 74, T-fitting 84 and conduit 86 to the carburetor. If desired a nonreturn valve of any conventional type may be applied to any of these conduits.

The arrangement is such that varying controllable proportions of liquid fuel may be applied directly to the carburetor and to the preheater.

A slightly modified construction of preheating tank is indicated in FIGURE 5. In this form the tank indicated by the numeral 99 has its open ends internally threaded as at 92 for receiving therein the two end walls of which one is indicated at 94. These end walls have diametrically reduced cylindrical externally threaded sleeves 96 thereon which engage with the threaded inte rior of the tank 90 to effect a fluid-tight seal therewith, the annular rim portion of the plates lying radially outwardly of the sleeve 92. having an abutting engagement with the ends of the sleeve as shown in FIGURE 5. Thus,

a detachable closure having a fluid-tight connection is established for the tank. The same construction of heating coil 79 having inlet and outlet portions 72 and 74 is provided as set forth in connection with FIGURE 3, and each of the end plates likewise is provided with the axially disposed tubular boss 93 to which the previously mentioned water inlet and outlet conduits 32 and 34 as previously mentioned are detachably connected as by the clamping means 64. The operation of this form of the invention is identical with that previously described.

it will thus be evident that by this attachment the efficiency of operation of the internal combustion engine skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A fuel supply system comprising in combination an internal combustion engine having a c rculating water cooling system, a carburetor and a fuel pump forsupplying fuel from a source of supply to said carburetor, a fuel preheater mounted on said engine adjacent said carburetor, connecting means communicating said preheater with said cooling system and circulating hot water through said preheater in a straight line flow with a minimum back pressure on said cooling system, means for circulating fuel to be heated in said preheater in heat exchange relation with the circulating hot water therein and in a path surrounding and extending substantially the entire length of but out of said straight line of flow of said hot water, a fuel supply conduit connecting said fuel pump with said connecting means and having a control valve therein, a heated fuel delivery conduit connecting said fuel circulating means to said carburetor, a fuel bypass conduit connecting said heated fuel delivery conduit to said fuel supply conduit between said valve and said fuel pump whereby to proportion the flow of fuel from said fuel pump to said pre heater fuel circulating means and to said carburetor.

2. The combination of claim 1 wherein said preheater comprises an elongated tank having end walls, said connecting means including conduits opening through said end walls and aligned with and communicating with the interior of said tank for unidirectional straight line flow of water therethrough, said fuel circulating means comprising a coil having convolutions spaced longitudinally of said tank and surrounding the line extending through said conduits whereby to effect a swirling motion of the hot water passing through said tank about said straight line of fiow.

3. A fuel preheater comprising a tank having opposed end walls, alined water inlet and outlet means each extending through an end wall and adapted for connection to the water cooling system of an internal combustion engine for effecting circulation of heated water through said tank in a path of straight line flow, a spiral heating coil disposed in said tank out of said path of straight line flow whereby to minimize resistance to water flow through said tank while being in good heat exchange relation to and being immersed in said circulating heated water, fuel supply and fuel delivery conduits for connecting the opposite ends of said coil respectively to a fuel pump and to an engine carburetor, bypass means connected to said fuel supply conduit and adapted for connection to said engine carburetor, said fuel supply conduit having a control valve therein, said bypass being connected 5 to said fuel supply conduit on the approach side of said valve.

4. The combination of claim 3, wherein said tank and said heating coil are cylindrical, with the coil and said path of straight line flow being located centrally of said tank and uniformly spaced from the side and end walls of the latter whereby the spiral convolutions of said coil will surround said path of straight line flow and effect a spiral swirling of the heated water circulated through said tank to thereby increase the rate and efiiciency of heat exchange between the water and coil.

5. The combination of claim 3 wherein said end Walls have outwardly and axially projecting tubular bosses communicating with the interior of said tank and in alignment with each other, said water inlet and outlet means being embracingly secured to said bosses, and said end walls comprise circular plates having diametrically reduced externally threaded sleeves engaged in the open ends of said tank with annular rim portions of said plates abutting the ends of said tank.

6. The combination of claim 5 wherein said -fuel supply and discharge means are secured to and extend through one of said plates.

7. The combination of claim 3 including a bracket secured to the exterior of said tank for mounting the latter on an engine.

References Cited in the file of this patent UNITED STATES PATENTS 1,168,111 Pope Jan. 11, 1916 1,300,600 Giesler Apr. 15, 1919 1,318,265 Clemmensen Oct. 7, 1919 1,391,709 Wood and Roewekemp Sept. 27, 1921 1,406,766 Shipp Feb. 14, 1922 1,623,074 Tartrais Apr. 5, 1927 2,231,525 Breitling Feb. 11, 1941 2,748,758 Fairbanks June 5, 1956 

1. A FUEL SUPPLY SYSTEM COMPRISING IN COMBINATION AN INTERNAL COMBUSTION ENGINE HAVING A CIRCULATING WATER COOLING SYSTEM, A CARBURETOR AND A FUEL PUMP FOR SUPPLYING FUEL FROM A SOURCE OF SUPPLY TO SAID CARBURETOR, A FUEL PREHEATER MOUNTED ON SAID ENGINE ADJACENT SAID CARBURETOR, CONNECTING MEANS COMMUNICATING SAID PREHEATER WITH SAID COOLING SYSTEM AND CIRCULATING HOT WATER THROUGH SAID PREHEATER IN A STRAIGHT LINE FLOW WITH A MINIMUM BACK PRESSURE ON SAID COOLING SYSTEM, MEANS FOR CIRCULATING FUEL TO BE HEATED IN SAID PREHEATER IN HEAT EXCHANGE RELATION WITH THE CIRCULATING HOT WATER THEREIN AND IN A PATH SURROUNDING AND EXTENDING SUBSTANTIALLY THE ENTIRE LENGTH OF BUT OUT OF SAID STRAIGHT LINE OF FLOW OF SAID HOT WATER, A FUEL SUPPLY CONDUIT CONNECTING SAID FUEL PUMP WITH SAID CONNECTING MEANS AND HAVING A CONTROL VALVE THEREIN, A HEATED FUEL DELIVERY CONDUIT CONNECTING SAID FUEL CIRCULATING MEANS TO SAID CARBURETOR, A FUEL BYPASS CONDUIT CONNECTING SAID HEATED FUEL DELIVERY CONDUIT TO SAID FUEL SUPPLY CONDUIT BETWEEN SAID VALVE AND SAID FUEL PUMP WHEREBY TO PROPORTION THE FLOW OF FUEL FROM SAID FUEL PUMP TO SAID PREHEATER FUEL CIRCULATING MEANS AND TO SAID CARBURETOR. 